1. Field of the Invention
The present invention relates to a method for manufacturing a semiconductor device wherein fixing materials are fixed on a surface of a package in which a semiconductor element is sealed with resin; a lamination and fixing materials used in the method; and a semiconductor device provided with fixing materials.
2. Description of Related Art
Conventionally, semiconductor devices such as transistors, ICs and LSIs have been sealed by the use of ceramic packages. Recently, in order to reduce costs and to facilitate mass production, among other reasons, semiconductor devices of the resin-sealed type using plastic packages have been widely used. In this type of resin-sealed semiconductor device, epoxy resin has been popular as a molding resin and has achieved good results. Technological innovation has resulted in the degree of integration of these semiconductors becoming higher and the layer dimensions becoming larger, and a strong demand has developed to reduce the dimensions of the packages. To this end, the volume ratio of the sealing resin material to the overall package has become small. Accordingly, there has arisen a further demand for improvement of the sealing resin characteristics, for example, in connection with the reduction in thermal stress, the reliability of moisture proofing, and the ability to withstand thermal shock.
More specifically, there has been a recent trend to increase the sizes of semiconductor elements, requiring a further improvement in the performance of semiconductor sealing resin with regard to the thermal cycle test (TCT test), which is an acceleration test for evaluating the performance of the semiconductor sealing resin. Further, surface mounting has become a common method for mounting a semiconductor package onto a circuit wiring board, resulting in a need for the semiconductor to resist cracking and bulging when it is dipped into molten solder after it has absorbed humidity.
In response to these demands and requirements, conventionally, in order to improve the respective characteristics evaluated in the TCT test, attempts have been made to use a silicone compound which may deform the epoxy resin to reduce thermal stress. Attempts have also been made to bring the semiconductor into tight contact with a lead frame in order to improve the anti-crack property required when a semiconductor package is dipped into molten solder. However, the results of these attempts have not been sufficient.